Mold box for block presses



June 16, 1925. v J. VAN HLLEN nloLn sox Fon BLOCK PRESSES Filed Oct.1'7, 1924 mv, ------.U fr C i cnA Patented June 16, 1925.

UNITED STATES PATENT OFFICE.

JOSEF VAN HLLEN, OF CREFELD, GERMANY.

MOLD BOX FORBLOCK PRESSES.

Application filed October 17, 1924. Serial No. 744,192.

` lowing is a specification.

This invention relates to a mold for celluloid block presses. In orderto facilitate the ejection of the celluloid blocks which after th-epressing adhere strongly to the mold walls, or in order to eect thisejecting with less pressure than usually the pressing faces are formed,according to the inventi-on, of conical plates which bear during thepressing against the also conical inner walls of the mold and form apressing space ofplane faces. These heatable plates rest during thepressing with their lower edges on shoulders of the mold faces and atthe ejecting of the pressed blocks they are lifted together with saidblocks Vby the adhesion action until their projections butt againstabu'tments of the molds. Owingrto the conical shape of the pressingplates a fre-e space is formed at the raising of said plates betweensaid plates and the walls of the mold so that, after having arrived attheir extreme position, they can give way in lateral direction and dropback into the initial position, the released Celluloid block being thencompletely removed from the mold. This arrangement.presents an advantagein so far as only the comparatively thin platesneed be heated, while inthe commonly used constructions, the considerably thicker walls of themold have to be heated. The mold box used may be in one part or composedof several parts. j

An embodiment of the invention is shown on the accompanying drawing inwhich a mold box composed of four part/s is shown by way of example.

Fig. 1 is a plan view of the mold top of a block press.

Fig. 2 is a section on line AMA, and Fig. 3 is a section on line B-B ofFig. 1.

The mold box of the block press is composed of four walls a, b, c, dheld together by screw bolts e. The inner edges of the ribs f extendfeebly conically. The conical plates g bear against these edges so thatthe inner space formed by the same is enclosed by vertical faces. Theplates g are connected with one another at the edges by tongueand-grooveconnection and they have inner channels i for the heating medium. Thelower edges of the plates g rest normally on shoulders of the walls ofthe mold box. J'lIhe plates g have projections m on the outer races.

If after the pressing the compress-ed material is ejected in thedirection of the arrow I the plates g are lifted also yowing 'to theadhesion which exists between them and the f compressed material, untilthe projections m strike against the abutments n. in 'the walls of themold box. Between the walls of the mold box and the plates g a freespace is formed owing to the conical shape of the plates s-o that afterthe plates have arrived at their extreme position they can give way inlateral direction and drop back onto the shoulders e. The compressedmaterial is then ejected without any lateral friction.

I claim 1. A mold box for block presses comprising in combination withthe box proper having conical inner walls, conical heatable platesbearing against said conical inner walls of the mold box so that aninner space is formed enclosed by vertical faces, projections on saidconical plates, and abutments von the inner walls of the mold box frrlimiting the movability of said heatable p ates.

2. A mold box for block presses comprising in combination with the boxproper having conical inner walls, conical heatable platesy bearingagainst said conical inner walls of the mold box so that an inner spaceis formed enclosed by vertical faces, groove-and-tongue connectionsbetween the adjacent edges of 'said heatable plates, projections on saidconical plates, and abut-ments on the inner walls of the mold box forlimiting the movability of`said heatable plates.

3. A mold box for block presses comprising in combination with the boxVproper having conical inner walls, shoulders on the inner walls of saidmold box, conical heatable plates bearing against said conical innerwalls of the mold box so that an inner space is formed enclosed byvertical faces, the lower edges of said plates resting normally on `saidshoulders of the mold box, projections on said conical plates, andabutments on the inner walls of the mold box for limit.- ing themovability of said heatable plates.

4. A mold box for block presses comprising in combination with the boxproper Walls of the mold box for limiting the movalmving conical inne-rWalls, ,conical liezitnble bility oi 'said -heatable ,pla-tes. 10 platesbearing against said eonieafl vinner In testimony whereof I zii'lix mysignature walls of the mold box so that an inner space ill PTG'SGIICE 0f21 WDQSS.

is formed enclosed` b f .vertical faces and having inner chzinnels5 forthe pzrssage of JOSEF VAN HLLEN the heating medium, projections Qn seid-Vi'tness:

conical plates, and abutments on 'the inner M. Form.

